Failure of quality control measures to prevent reporting of false resistance to imipenem, resulting in a pseudo-outbreak of imipenem-resistant Pseudomonas aeruginosa.
False results showing an outbreak of Pseudomonas aeruginosa with resistance to imipenem were traced to a defective lot of microdilution MIC testing panels. These panels contained two- to threefold lower concentrations of imipenem than expected and resulted in artifactual two- to fourfold increases in MICs of imipenem. The quality-control MIC results for Pseudomonas aeruginosa ATCC 27853 were 4 microg/ml, the highest value within the range recommended by the National Committee for Clinical Laboratory Standards. We recommend that this value be considered out of the quality-control range.
Carmeli
Y
Y
Division of Infectious Diseases, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA. ycarmeli@bidmc.harvard.edu
Eichelberger
K
K
Soja
D
D
Dakos
J
J
Venkataraman
L
L
DeGirolami
P
P
Samore
M
M
D016022:Case-Control Studies; D003951:Diagnostic Errors; D004196:Disease Outbreaks; D004352:Drug Resistance, Microbial; D005189:False Positive Reactions; D015378:Imipenem / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000379:methods*; D011552:Pseudomonas Infections / Q000175:diagnosis* / Q000188:drug therapy* / Q000453:epidemiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D011786:Quality Control; D013845:Thienamycins / Q000494:pharmacology*
D013845:Thienamycins; D015378:Imipenem